1. Field
Example embodiments relate to an organic electro-luminescent display device, and more particularly, to an organic electro-luminescent display device having improved uniformity of a thin film in a pixel area.
2. Description of the Related Art
In general, a flat display device may be classified as a non-emissive type or as an emissive type. An emissive type display device may include a flat cathode ray tube, a plasma display panel, an electro-luminescent device, and a light emitting diode display. A non-emissive type display device may include a liquid crystal display (LCD). For example, the electro-luminescent devices may have a wide viewing angle, excellent contrast, and high response speed. An electro luminescent device may be classified as an inorganic electro luminescent device or as an organic electro luminescent device based on a material used in forming an emission layer.
An organic electro luminescent device is a self-emissive display device that may emit light by electrically exciting a fluorescent organic compound and may be operated using a low voltage. In addition, an organic electro luminescent device may have a thin structure, a wide viewing angle, and a rapid response speed.
A conventional organic electro-luminescent device may include an emission layer formed of an organic material and interposed between an anode and a cathode. In the organic electro-luminescent device, when a positive voltage and a negative voltage are applied to the anode and the cathode, respectively, a hole injected from the anode is moved to the emission layer through a hole transport layer (HTL) and an electron is moved to the emission layer from the cathode through an electron transport layer (ETL). The hole and electron may combine in the emission layer to generate an exciton. As the excitons change from an excited state to a ground state, fluorescent elements in the emission layer emit light, and thus, an image may be formed. In a full-color type organic electro-luminescent device, pixels having three colors, e.g., red (R), green (G), and blue (B), may be included to realize full color.
In such an organic electro-luminescent device, a pixel define layer may be formed at both ends of the anode. When a predetermined opening is formed on the pixel define layer, the emission layer and the cathode may be sequentially formed on portions of the anode exposed to the outside through the opening.